Grotiana 41 (2) 2020, p. 371-389 Grotius and Late Medieval Ius Commune on Rebellion and Civil War Dante Fedele, Chargé de recherche Univ. Lille, CNRS, UMR 8025 – CHJ – Centre d’histoire judiciaire, F-59000 Lille, France [email protected] Abstract: This paper explores the presence of late medieval ius commune in Grotius’s thought on the use of force in internal strife and war, based on De iure belli ac pacis (1625). To this end, it examines Grotius’s use of ius commune sources, and considers some similar sources, which he does not actually cite, but which relate to his discussion. By clarifying Grotius’s selection and use of ius commune sources, the paper intends to contribute to the achievement of a double aim: firstly, to determine the place of rebellion and civil war in De iure belli ac pacis, especially in relation to (external) war; and, secondly, to assess Grotius’s approach to the two former issues, particularly with regard to the criteria by which a distinction between rebellion and civil war can be drawn, and to the effects of this distinction. Keywords: Grotius, Ius commune, Rebellion, Civil War, Use of force This paper explores the presence of late medieval ius commune in Grotius’s thought on the use of force in internal strife and war, based on De iure belli ac pacis (1625). To this end, it examines Grotius’s use of ius commune sources, and considers some similar sources, which he does not actually cite, but which relate to his discussion and can be fruitfully studied to broaden the scope of the analysis. By clarifying Grotius’s selection and use of ius commune sources, the paper intends to contribute to the achievement of a double aim: firstly, to determine the place of rebellion and civil war in De iure belli ac pacis, especially in relation to (external) war; and, secondly, to assess Grotius’s approach to the two former issues, particularly with regard to the criteria by which a distinction between rebellion and civil war can be drawn, and to the effects of this distinction. One obvious starting point for this kind of investigation is Robert Feenstra’s annotation of De iure belli ac pacis, which guides us neatly through the numerous sources cited by Grotius in his magnum opus, and enables the reader to appreciate the strong presence of ius commune jurisprudence.1 Feenstra also provided an overview of this subject in an 1 See H. Grotius, De iure belli ac pacis libri tres, curavit B.J.A. De Kanter - Van Hettinga Tromp (1939), annotationes novas addiderunt R. Feenstra et C.E. Persenaire (Aalen: Scientia Verlag, 1993), hereafter cited as 1 Grotiana 41 (2) 2020, p. 371-389 article which appeared in 1992, in which he demonstrates that Grotius sometimes had direct knowledge of the works he cited (although when writing De iure belli ac pacis he had no longer access to his personal library), and sometimes relied on second-hand references to medieval jurists (in the works of early modern scholars like Francisco de Vitoria, Alberico Gentili, Diego de Covarrubias and Fernando Vázquez de Menchaca, in particular).2 A ground-breaking study in the field – predating Feenstra – was Peter Haggenmacher’s Grotius et la doctrine de la guerre juste, which is especially relevant to our analysis insofar as it focuses on war and the use of force, and – through careful analysis of both De iure praedae and De iure belli ac pacis – assesses the presence of ius commune authorities in these works.3 Subsequently, James Muldoon studied Grotius’s use of medieval canon law in Mare liberum (1609), in order to show how the Dutch jurist, although he used the same source material as his Spanish predecessors, actually elaborated a different conception of the international order, criticising the idea of a trade monopoly based on papal donation, and asserting a basis for trade freedom in natural law.4 More recently, Robert Fredona has investigated the presence of late medieval jurisprudence in Mare liberum, insisting on the ‘technical legal character’ of this work and its scholarly apparatus, which includes ‘an average of 2.25 mentions’ of Roman, canon, and feudal law texts or commentaries per page, and features Bartolus de Sassoferrato and Baldus de Ubaldis as the most cited authors of that tradition.5 IBP. Translations are from H. Grotius, De jure belli ac pacis libri tres, transl. F.W. Kelsey (Oxford: Clarendon Press, 1925). 2 See R. Feenstra, ‘Ius commune et droit comparé chez Grotius: nouvelles remarques sur les sources citées dans ses ouvrages juridiques, à propos d’une réimpression du De iure belli ac pacis’ (1992), in Id., Legal Scholarship and Doctrines of Private Law, 13th-18th Centuries (Aldershot: Variorum, 1996). See also Feenstra’s Introduction to H. Grotius, Mare Liberum, 1609-2009: Original Latin Text [...] and Modern English Translation, ed. R. Feenstra (Leiden-Boston: Brill, 2009), pp. LVI-LIX. Further studies on Grotius by Feenstra are mentioned in A. Wijffels, ‘Legal Scholastic and Humanist Influences on Grotius’, in The Cambridge Companion to Hugo Grotius, ed. R. Lesaffer and J. Nijman (Cambridge: Cambridge University Press, forthcoming). On Grotius’s working method, see M.J. van Ittersum, ‘The Working Methods of Hugo Grotius: Which Sources Did He Use and How Did He Use Them in His Early Writings on Natural Law Theory?’, in Reassessing Legal Humanism and its Claims. Petere Fontes?, ed. P.J. du Plessis and J.W. Cairns (Edinburgh: Edinburgh University Press, 2016), pp. 154-93. 3 See P. Haggenmacher, Grotius et la doctrine de la guerre juste (Paris: PUF, 1983). See also Id., ‘Grotius and Gentili: A Reassessment of Thomas E. Holland’s Inaugural Lecture’, in Hugo Grotius and International Relations, ed. H. Bull, B. Kingsbury and A. Roberts (Oxford: Clarendon Press, 1990), pp. 133-76. 4 See J. Muldoon, ‘Hugo Grotius, Medieval Canon Law and the Creation of Modern International Law’, in Proceedings of the Ninth International Congress of Medieval Canon Law, Munich, 13-18 July 1992, ed. P. Landau and J. Mueller (Città del Vaticano: Biblioteca Apostolica Vaticana, 1997), pp. 1155-65, with further references. On the issue of free trade in Grotius’s thought, however, see M. Somos, ‘Open and Closed Seas: The Grotius-Selden Dialogue at the Heart of Liberal Imperialism’, in Empire and Legal Thought. Ideas and Institutions from Antiquity to Modernity, ed. E. Cavanagh (Leiden/Boston: Brill/Nijhoff, 2020), pp. 322-61. 5 See R. Fredona, ‘Angelo degli Ubaldi and the Gulf of the Venetians: Custom, Commerce, and the Control of the Sea Before Grotius’, in New Perspectives on the History of Political Economy, ed. R. Fredona and S.A. Reinert (Cham: Plagrave Macmillan, 2018), pp. 29-73: 30. Taking his lead from a reference found in H. Grotius, Mare liberum, p. 101 (p. 39 in the original edition of 1609), Fredona examines in particular Angelus de Ubaldis’ consilium 290 (289 in some incunabula). Angelus’s opinion deals with a clause of the peace treaty concluded in 1355 between Venice and Genoa, which regulated the freedom of navigation in the Adriatic and the Tyrrhenian, and was later also included in the treaty entered into by the two cities in 1381. Since Grotius, as already noted by Feenstra, copied the reference to Angelus from Giovanni Francesco Balbo’s Tractatus de 2 Grotiana 41 (2) 2020, p. 371-389 Grotius’s categorisation of war in De iure belli ac pacis is well known.6 He starts from a distinction between ‘private war’ (fought by private persons), ‘public war’ (fought by people invested with jurisdiction) and ‘mixed war’ (which is private on the one side, and public on the other). Public war is then divided into two sub-categories, i.e. ‘formal (solenne)’ on the one hand (which requires two conditions: a formal declaration of war, and the sovereignty of both belligerent parties),7 and ‘less formal (minus solenne)’ on the other (which is defined by the absence of either of these conditions). Internal strife and war fall under the category of ‘mixed war’ – they are, in fact, the only instance of mixed war that Grotius discusses (I.4). However, he also examines them in his analysis of ‘less formal public war’ (I.3). Actually, these two chapters seem to reflect different perspectives: in chapter 3 Grotius considers rebellion from the viewpoint of the public official (who has the authority to repress rebellion), whereas in chapter 4 he considers the same issue from the viewpoint of private persons (who normally enjoy no right of resistance). Internal strife and war are also touched upon in other passages of De iure belli ac pacis, including those on the right to send ambassadors (II.18.2.3), the right of burial (II.19.4), going to war on behalf of others (II.25.8), formal war (III.3.1), the right to appropriate objects captured in war (III.6.27), the rights over prisoners of war (III.7.5.3 and III.7.7), and the keeping of good faith with enemies (III.19.6-10). This paper is divided into two parts. In the first, it deals with rebellion and its relation to the notion of war (bellum); in the second, it concentrates on civil war and – in particular – some medieval antecedents of Grotius’s conceptualisation of the two belligerent parties as two distinct gentes. Rebellion When he discusses less formal public war, in I.3.4, Grotius begins by presenting the opinion that not every public official has the authority to ‘wage war for the protection of the people entrusted to his charge’, since war can only be waged under the authority of the holder of the ‘sovereign power in the state (summa in civitate potestatem)’.8 He refers to Plato’s Laws (12.7), and to both Roman and canon law: lex Iulia maiestatis is cited,9 as are a constitution by Valentinian and Valens (from 364), and an excerpt from Augustin included in Gratian’s Decretum.10 All of these sources state that the order to take up arms can only be issued by the princeps – a principle which is duly emphasised by the glosses to all these Roman and praescriptione, Fredona uses this as a case-study about Grotius’s ‘second-hand erudition’, see ibid., p.